Chk1 activation requires Rad9 S/TQ-site phosphorylation to promote association with C-terminal BCRT domains of Rad4TOPBP1
Chk1 activation requires Rad9 S/TQ-site phosphorylation to promote association with C-terminal BCRT domains of Rad4TOPBP1
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DOI：
10.1101/gad.291104
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发表时间：
2004-05-15
影响因子：
10.5
通讯作者：
Carr, AM
中科院分区：
文献类型：
--
作者：
Furuya, K;Poitelea, M;Carr, AM
为了深入了解DNA上组装的蛋白质响应于遗传毒性损伤的功能和组织，我们研究了粟酒裂殖酵母PCNA样检查点蛋白Rad的磷酸化（9）。在没有复制应激的情况下，Rad 3（ATR）对Rad 9的C-末端T412/S423磷酸化发生在S期。Rad 3（ATR）和Tel 1（ATM）磷酸化这些相同的残基，加上额外的残基，以响应DNA损伤。在S期和损伤后，只有Rad 9磷酸化的T412/S423，而不是未磷酸化的Rad 9，与两个BRCT结构域区域的必需Rad 4（TOPBP 1）蛋白。Rad 9-Rad 4（TOPBP 1）相互作用是激活Chk 1损伤检查点而不是Cds 1复制检查点所必需的。当Rad 9-T412/S423被磷酸化时，Rad 4（TOPBP 1）与Rad 3（ATR）共沉淀，表明磷酸化协调活性检查点复合物的形成。
To gain insight into the function and organization of proteins assembled on the DNA in response to genotoxic insult we investigated the phosphorylation of the Schizosaccharomyces pombe PCNA-like checkpoint protein Rad(9). C-terminal T412/S423 phosphorylation of Rad9 by Rad3(ATR) occurs in S phase without replication stress. Rad3(ATR) and Tel1(ATM) phosphorylate these same residues, plus additional ones, in response to DNA damage. In S phase and after damage, only Rad9 phosphorylated on T412/S423, but not unphosphorylated Rad9, associates with a two-BRCT-domain region of the essential Rad4(TOPBP1) protein. Rad9-Rad4(TOPBP1) interaction is required to activate the Chk1 damage checkpoint but not the Cds1 replication checkpoint. When the Rad9-T412/S423 are phosphorylated, Rad4(TOPBP1) coprecipitates with Rad3(ATR), suggesting that phosphorylation coordinates formation of an active checkpoint complex.